During the past years there have been a number of signaling devices which have been provided for automobiles for the purpose of warning when various abnormal situations occur especially with the engine. One of these in particular deals with a light which indicates when the pressure in the engine lubricating oil system has dropped below a predetermined value. It is well known that if the oil pressure should drop below a specific level or is lost completely, the engine is in danger of being permanently damaged through lack of lubrication. By the same token it is highly important that the oil that is flowing through the engine be clean and free of contaminants to allow the engine to run properly so that the vehicle can be driven for many miles.
In order to maintain the oil in this relatively clean condition it is common to include an oil filter on the engine which has a spin-on or cartridge type filter element. The oil filter attaches to a permanently mounted bracket positioned on the side of the engine. The bracket is connected to an oil passage coming directly from the lubricating oil pump found in the pan of the engine and directs the oil in the proper channel through the filter element with the return flow going to the various bearings and critical parts within the engine.
The mounting bracket also generally contains a bypass valve so that if the oil is heavily contaminated and blocks the pores of the oil filter element causing the flow to be greatly restricted or reduced, the bypass valve will be forced to open allowing the incoming oil to bypass directly to the outlet and to the engine to prevent any complete blockage and thus, loss of lubrication.
The applicants are unaware of any device that is presently on the market to warn the operator of the vehicle when the oil filter element is no longer performing its intended function of filtering foreign material and contaminants from the lubricating oil.
The most common method used at present is to replace the oil filter at various time or mileage intervals as specified by the vehicle manufacturer. On engines that usually run clean the oil filter could still be operating efficiently when this interval is reached. And in very dirty engines or engines which are run in a very dusty climate, it is highly possible that the oil filter could be completely plugged or inoperative long before the interval is reached. Thus, if the filter becomes plugged or clogged, the contaminated lubricating oil which is bypassed contains abrasive materials that could cause rapid wear of the moving parts of the engine.
The present invention is designed to warn the operator before the oil filter becomes entirely inoperative causing the oil to bypass the filter. In most cases where the oil filter is still functioning properly when the recommended mileage or time interval is reached, the use can continue which will eliminate unnecessary replacement of the filter element and the additional oil required when the new oil filter element is installed.